1. Chapter 16 Section 3 The Process of Speciation AZ State Science Standards S4C4PO1: Identify the following components of natural selection, which can lead to speciation: potential for a species to increase its numbers; genetic variability and inheritance of offspring due to mutation and recombination of genes; finite supply of resources required for life; selection by the environment of those offspring better able to survive and produce offspring S4C4PO2 Describe how the continuing operation of natural selection underlies a population’s ability to adapt to changes in the environment and leads to biodiversity and the origin of new species Objectives: -Identify the condition necessary for a new species to evolve -Describe the process of speciation in the Galapagos finches

2. Evolution of Corvette List three adaptations that have occurred and the pressures that may have caused these changes

3. Speciation: Changes that lead to the formation of new species Species- A group of organisms that breed with one another and produce fertile offspring (progeny)… which means they share a common gene pool

4. Isolating Mechanisms: In order for a species to evolve into a new species, the gene pools of two populations must become separated…they must become reproductively isolated from one another

5. Isolating Mechanisms Con’t: Behavioral Isolation: -Occurs when two populations are capable of interbreeding but have differences in courtship rituals or other reproductive strategies For example: eastern vs western and songs that attract mateseastern western

6. Isolating Mechanisms Con’t: Geographic Isolation: – Occurs when barriers such as rivers, mountains, etc separate two populations – For example: Albert and Kaibab Squirrels are separated by the Grand Canyon

8. Isolating Mechanisms Con’t: Temporal Isolation: -Two or more species reproduce at different times For example: Three similar species of orchid release pollen on different days, thus they are unable to pollinate one another

9. Temporal Isolation

10. Darwin’s Finches Read pages 408-409 What type of isolating mechanism was important in the formation of Galapagos finch species?